OBJECTIVE

2

To investigate the effects of safflower polysaccharide （SPS） on ischemic stroke （IS） in rats by regulating the growth arrest-specific protein 6 （Gas6）/Axl receptor tyrosine kinase （Axl） signaling pathway.

METHODS

2

The modified suture-occluded method was employed to establish a rat model of middle cerebral artery occlusion （MCAO） for IS. The rats were then randomly divided into the model （Model） group， SPS low- and high-dose （SPS-L， SPS-H， 50 and 100 mg/kg） groups， and integrated traditional Chinese and Western medicine （SPS-H+Nim， SPS 100 mg/kg+Nim 15 mg/kg） group， with 10 rats in each group. Another 10 rats were selected as the sham operation （Sham） group. Rats in each group were administered corresponding doses of medication or an equal volume of normal saline intragastrically， with continuous intervention for 14 days. The neurological function of rats in each group was evaluated 24 hours after drug administration. The morphological changes in hippocampal tissue were observed. The contents of interleukin-6 （IL-6）， IL-1β， and tumor necrosis factor-α （TNF-α） in serum， the percentage of cerebral infarction area， the neuronal apoptosis rate， as well as the contents of malondialdehyde （MDA）， superoxide dismutase （SOD）， and brain-derived neurotrophic factor （BDNF） in hippocampal tissue， and the relative protein expression levels of Gas6， phosphorylated Axl （p-Axl）， Axl， B-cell lymphoma-2 （Bcl-2）， and Bcl-2 associated X protein （Bax） were measured.

RESULTS

2

Compared with Model group， the neurological function of rats in SPS-L group， SPS-H group and SPS-H+Nim group improved significantly， while serum contents of IL-6， TNF-α， and IL-1β， the percentage of cerebral infarction area， the apoptotic rate of neurons as well as MDA content and relative protein expression of p-Axl and Bax were decreased significantly （

P

＜0.05 or

P

＜0.01）. The contents of SOD and BDNF， as well as the relative protein expression of Gas6， Axl， and Bcl-2 in hippocampal tissue， were significantly increased （

P

＜0.05 or

P

＜0.01）， and the ischemic injury in hippocampal tissue imp

roved to varying degrees.

CONCLUSIONS

2

SPS can reduce neuroinflammation， oxidative stress， and neuronal apoptosis in IS rats， alleviate nerve injury， and improve neurological function， which may be achieved by activating the Gas6/Axl signaling pathway.